The concept of time travel is a fascinating topic that has captured the imagination of many, but it remains highly speculative and has not been proven possible according to our current understanding of physics. However, I can provide an overview of the current scientific understanding and some theoretical possibilities.
According to Einstein's theory of relativity, time can be influenced by factors such as motion and gravity. Time dilation, as predicted by this theory, suggests that time can run at different rates depending on these factors. In certain scenarios, such as near the event horizon of a black hole, extreme gravitational forces could potentially result in time dilation, where time appears to move slower for an observer compared to someone further away from the intense gravitational field.
However, when it comes to traveling back in time, the scientific consensus is that it poses significant challenges and is currently considered highly unlikely. One major obstacle is the violation of causality, which is the principle that an event cannot occur before its cause. Traveling back in time could lead to paradoxes, such as the famous "grandfather paradox" where one could potentially prevent their own birth by changing the past.
As for traveling back to before the Big Bang, our current understanding of physics breaks down when it comes to explaining the conditions that existed before the Big Bang. The laws of physics, as we know them, may not apply in that extreme and unknown environment. Therefore, it is currently unknown what would happen if one could travel back to that point, as it lies beyond the realm of our current understanding.
It's important to note that speculation and theories about time travel often exist within the realm of science fiction and are the subject of ongoing scientific exploration and debate. While it's an intriguing concept, the practical realization of time travel and its consequences remain speculative and uncertain based on our current scientific knowledge.